Durango in Trouble AGAIN!

Just recently has trouble and had spark plugs, wires and thermostat changed (my '99 Durango over heats every single summer so we have to have a new thermostat put in every winter so it will warm up and run better and then
changed to a much cooler one in the summer so I don't overheat on the 11 miles home from work.) Anyhow, it's acting up again. I have the biggest engine available in the '99. Acts like it's not getting enough gas. No problems when the car is real cold, but the warmer it gets the worse it runs. Like driving a train, it chugs. My budget can't take another hit, Already have $5,000 in this thing since a new transmission was put in at 76,000 miles last December. Any advice? PLEASE DON"T TELL ME TO GET RID OF IT. I"M ALREADY IN THE MARKET FOR A CHRYDLER PACIFICA but I want to keep this for my 17 year old son as this car as been rear ended 3 times and I've come out the winner each time with the other cars completely totaled! All I ever need is a new bumper and hitch.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

with the thermostats like you do. The computer needs to see your vehicle hit operating temperature.
I'd suggest you find a capable mechanic and figure out how to fix the problem; I'd be suprised if your summer overheating and winter chugging problem aren't related.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.